Uv hardening glass printing ink and uv hardening glass printing lacquer and method for printing a glass substrate

ABSTRACT

A glass printing ink and a glass printing lacquer comprising at least one pigment, at least one photoinitiator, at least two resins and radicial photoinitiators. One resin is an epoxy resin having an average molecular weight based on bisphenol A, diluted in a UV hardening monomer. The other resin is a resin which contains free functional amino, hydroxy, epoxy, acid, acid anhydride and/or acrylate groups. Also, the use of the glass printing ink and glass printing lacquer when printing a glass substrate and to a method for printing a glass substrate.

RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 10/576,706 which has a filing/371(c) date of Jan.8, 2007, which is a national phase application of PCT Patent ApplicationPCT/EP2004/011858, filed Oct. 20, 2004, which claims the filing benefitof DE 103 49 394.8, filed Oct. 21, 2003, all of which are incorporatedherein by reference.

FIELD OF THE INVENTION

The invention relates to a UV hardening glass printing ink and a UVhardening glass printing lacquer, preferably for printing a glasssubstrate or printing lacquer.

BACKGROUND OF THE INVENTION

In recent times, increasing use has been made in glass printingapplications of UV hardening organic glass printing inks, which must besubjected to thermal post-treatment after hardening, instead of thepreviously used ceramic (inorganic) inks. This makes it possible toavoid the use of heavy metals, to gain access to a greater colour range(standard and mixed shades) and to achieve greater brightness and anelevated degree of gloss. Another advantage is the possibility to assessthe colour shade directly after UV hardening. In contrast thereto,inorganic inks cannot be assessed until after stoving. They furthermoreoffer processing advantages, such as a faster heat treatment process(for example approx. 20 min in comparison with 90 min heat treatment)and a reduced heat treatment temperature (for example 160° C. incomparison with 500-700° C.), so reducing processing costs in comparisonwith processes using inorganic glass printing inks. The organic glassprinting inks themselves, however, are more costly than conventionalinorganic inks for printing glass.

The milder processing conditions in the printing method with organicglass printing inks ensure that the internal pressure resistance ofbottles is not impaired. Organic glass printing inks are, however, notsuitable for printing glass which must be post-treated at elevatedtemperatures, such as moulded glass for automotive applications or glasswith high gloss gold print.

With currently available organic printing inks for glass, problems mayarise in relation to covering power, mechanical resistance and waterresistance. After a glass pretreatment, for example flame treatment,organic printing inks for glass are printed in a two-component printingmethod, i.e. with a coupling agent to be mixed into the printing ink,and then subjected to thermal post-treatment at temperatures of forexample 140-200° C. for a specific period.

It would be desirable to simplify this printing method and so reducecosts. One option for simplification would be to eliminate therequirement to use a two-component printing process, i.e. to use acoupling agent. Another option would be to make thermal post-treatmentsuperfluous.

WO 99/06336 discloses a method for printing glass, in which a glass ink,which comprises a bisphenol A epoxy resin is printed onto a glasssubstrate and is then hardened by means of radiation, wherein a couplingagent is optionally used.

The inventor found, however, that, without further measures, such aglass printing ink and such a method do not yield either adequateadhesion of the glass ink to the glass substrate or adequate scratch andwater resistance. Accordingly, in all the Examples of WO 99/06336, botha coupling agent was used and thermal post-treatment was performed at atemperature of 150° C. to 200° C. U.S. Pat. No. 5,656,336 A discloses asimilar process, which also suffers from the same shortcomings.

The present invention is directed to resolving these and other matters.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a glass printing inkand a glass printing lacquer which ensure adequate adhesive strength andscratch resistance without thermal post-treatment. A further object isto provide a use of the glass printing ink and of the glass printinglacquer in printing glass substrates and to provide an associatedprinting method.

These objects may be achieved by a glass printing ink and a glassprinting lacquer according to one or more solutions disclosed hereinand/or by a printing method disclosed herein.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

While this invention is susceptible of embodiment in many differentforms, there will herein be described in detail one or more embodimentswith the understanding that the present disclosure is to be consideredas an exemplification of the principles of the invention and is notintended to limit the invention to the embodiments illustrated.

One important advantage of the invention, apart from the mechanicalproperties of the cured ink or lacquer layer, is that the method issimplified in that, in both single component systems and two componentsystems, the desired mechanical properties are achieved without thermalpost-treatment. Moreover, good resistance to moisture and water isobtained in many cases.

A glass printing ink and glass printing lacquer are taken to mean aprinting ink or a printing lacquer which are suitable for printing onglass and vitreous surfaces, such as ceramics and tiles.

The glass printing ink according to the invention and the glass printinglacquer according to the invention contain as the resin constituent abisphenol A based epoxy resin which preferably has a molecular weight inthe range from 800 to 1500 (weight average). Such epoxy resins arecommercially available. Particularly preferred examples areRiitapox-Harz 0194 from Bakelite AG; ARALDITE® GT 7072 from Vantico AG,K-401.1.32, CH-4002 Basel and Epikote 1055 from Brenntag.

The epoxy resin used according to the invention is dissolved in amonomer which is UV hardening, for example due to acrylate groupssuitable for polymerisation. This monomer preferably comprises mono-,di- or higher polyacrylates or methacrylates, such as for exampleisobornyl acrylate, 2-phenylethyl acrylate, 2-(2-ethoxyethoxy)ethylacrylate (EOEOEA), 1,6-hexanediol diacrylate (HDDA), dipropylene glycoldiacrylate (DPGDA), neopentyl glycol diacrylate, dipentaerythritolhexaacrylate (DPHA), propoxylated glycerol triacrylate (GPTA),tripropylene glycol diacrylate, (TPGDA), dipentaerythritol pentaacrylate(DiPEPA), pentaerythritol triacrylate (PETIA), ethoxylatedtrimethylpropane triacrylate (TMPEOTA), dipentaerythritol acrylate(DPHA), tricyclodecanedimethanol diacrylate (TCDDMDA), hydroxypropylmethacrylate (HPMA). 1,6-Hexanediol diacrylate is very particularlypreferred.

The concentration of the epoxy resin in the monomer preferably amountsto 10 to 90 wt. %, preferably to 30 to 70 wt. %, very particularlypreferably to 50 wt. %, relative to the mixture.

The concentration of the epoxy in the glass printing ink according tothe invention and the glass printing lacquer according to the inventionis generally 1 to 90 wt. % dry weight, relative to the total mass of theglass printing ink or of the glass printing lacquer; it preferablyamounts to 5 to 20 wt. %, particularly preferably to 11 to 14 wt. % dryweight.

The glass printing ink according to the invention and the glass printinglacquer according to the invention additionally contain at least onefurther resin which comprises free functional amino, hydroxy, epoxy,acid, acid anhydride and/or acrylate groups. Resins which have provedparticularly suitable are melamine acrylate resins (for example thesilicon dioxide-reinforced NANOCRYL XP 21/0793 from Hanse Chemie (hansechemie GmbH, Charlottenburgerstrasse 9, D-21502 Geesthacht, Germany) orthe multifunctional melamine acrylate ACTILANE 890 from Akzo NobelResins (Akzo Nobel Resins by, German sales office, Industriestrasse 8,P.O. Box 100265, D-46422 Emmerich); Viaktin VTE 5967 from SurfaceSpecialities UCB, Anderlechtstr. 33, B-1620 Drogenbos, and anacid-modified polyester acrylate (for example GENOMER* 7154 from Rahn,Dörflistrasse 120, Zurich, Switzerland; Ebecryl 770 from SurfaceSpecialities UCB). Further suitable resins for combination are certainpolyester resins (for example Roskydal UA XP 2416 from Bayer, Ebecryl524 from Surface Specialities UCB) and epoxy acrylates (for exampleInchemrez W 931B50 from In Chem. Corp, P.O. Box 69, CH 1170 Aubonne).

The quantity of this further resin in the glass printing ink or theglass printing lacquer may vary widely. In general, the quantity is 5 to90 wt. % dry weight, relative to the total mass of the glass printingink or of the glass printing lacquer, preferably 5 to 40 wt. %,particularly preferably 10 to 30 wt. %. The purpose of this furtherresin is to make the glass printing ink or glass printing lacquer morepliable and less brittle and to increase the adhesion and scratchresistance thereof.

The glass printing ink according to the invention and the glass printinglacquer according to the invention may furthermore optionally alsocontain additional resins for further enhancement of the propertiesthereof. These resins may be selected from a wide range of resins, forexample methyl methacrylate copolymers (for example Paraloid B-48N,Paraloid B60, Paraloid B-82 from Rohm & Haas Deutschland GmbH, In derKron 4, D-60439 Frankfurt; Neocryl B-810 from Neoresins, Lurgiallee,D-60439 Frankfurt/Main); ethyl methacrylate (for example Paraloid B 72from Rohm & Haas); butyl methacrylate copolymers (for example Degalan LP65/12, Degalan LP 68/04 from Röhm GmbH & Co. KG, Kirschenallee, D-64293Darmstadt); liquid epoxy resins (for example Polypox E 064 from UPPCGmbH, Riitapox-Harz 0164 from Bakelite AG, Araldite GY 250 fromVantico); unsaturated polyester resins (for example Haftharz LTH fromDegussa Chemiepark Marl, Paul-Baumann-Str. 1, D-45764 Marl); saturatedpolyester resins (Dynapol L 912, Dynapol L 952 from Degussa).

Such additional resins may be present, for example, in a quantity of 1to 50 wt. % dry weight, preferably of 3 to 10 wt. %, relative to thetotal mass of the glass printing ink or of the glass printing lacquer.

The glass ink according to the invention and the glass printing lacqueraccording to the invention contain at least one photoinitiator, usuallytwo and possibly three or more photoinitiators, in order to initiatesurface and deep hardening (crosslinking) of the glass ink under UVlight. They may be selected from among conventional photoinitiators usedin UV hardening printing inks and lacquers etc., for example, withoutbeing limited thereto, 1-hydroxycyclohexylacetophenone (Irgacure® 184from Ciba SPEZIALTÄTEN-CHEMIE AG; Klybeckstrasse 141, Postfach, CH-4002Basel), 2-methyl-1-[4-(methylthio-phenyl)-2-morpholinopropan]-1-one(Irgacure 907® from Ciba),2-benzyl-2-dimethylamino-1-(4-morpholino-phenyl)-butan-1-one (Irgacure®369 from Ciba), bis(2,4,6-tri-methylbenzoyl)phenylphosphine oxide(Irgacure® 819 from Ciba), 2-hydroxy-2-methyl-1-phenyl-1-propanone(Darocur® 1173 from Ciba), isopropylthioxanthone (ITX from Lambson),2-chlorothioxanthone (CTX from Lambson), benzophenone,2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO from BASF), ethyl2,4,6-trimethylbenzoyl-phenylphosphinate (TPO-L from BASF) andmethylbenzoyl formate (MBF from Lambson). The total quantity ofphotoinitiators generally amounts to 1 to 12 wt. %, preferably to 3 to 7wt. %, relative to the total mass of the glass printing ink or of theglass printing lacquer.

Co-initiators may additionally be present, such as amines (for exampleMDEA from BASF, BASF Aktiengesellschaft, Carl-Bosch-Straβe 38, D-67056Ludwigshafen) or amine-modified acrylates (for example Ebecryl P 115,Ebecryl 7100 from Surface Specialities UCB; Actilane 705, Actilane 715,Actilane 755 from Akzo Nobel Resins by, German sales office,Industriestrasse 8, D-46446 Emmerich; Laromer PO 94 F, Laromer LR 8869from BASF; Craynor 503, Craynor 550 from Cray Valley, Immeuble leDiamant B, F-92970 Paris la Défense; Photomer 4775F from Cognis) inquantities of 1 to 5 wt. %, relative to the total mass of the glassprinting ink or of the glass printing lacquer.

The pigments present in the glass printing ink according to theinvention may comprise any desired pigments, for example titaniumdioxide, zinc sulfide, pigment black, azodiaryl yellow, isoindoleyellow, diarylide orange, quinacridone magenta, diketopyrrolo red,copper phthalocyanine blue, copper phthalocyanine green, dioxazineviolet and diketo metal oxide. A fairly comprehensive list of furtherusable pigments is published in Colour Index International, FourthEdition Online, 2001, published by the Society of Dyers and Colouristsin conjunction with the American Association of Textile Chemists andColorists. Special effect pigments, such as metal oxide-coated mica andmetallic pigments, may also be used.

The quantity of coloured pigment usually amounts to 2 to 50 wt. %,preferably to 10 to 35 wt. %, relative to the total mass of the glassprinting ink, depending on the type of pigment and the desired coveringpower. White pigment is normally used in a quantity of 20 to 50 wt. %,preferably of 30 to 40 wt. %.

The glass printing lacquer does not generally contain any pigment.

In general, further reactive diluents are added to the glass printingink or the glass printing lacquer in addition to the UV hardeningmonomer, in which the bisphenol A based epoxy resin is dissolved. Thesereactive diluents, which are likewise UV hardening, may comprise themonomers discussed above in connection with the polyester solution.Still further compounds with a single ethylenically unsaturated bond mayfurthermore also be used, such as for example N-vinylpyrrolidone (NVP)and vinyl caprolactam. The quantities of additional reactive diluentused generally amount to 0 to 60 wt. %, preferably to 3 to 20 wt. %, inparticular to 4 to 8 wt. %, for example to 6 to 7 wt. %, relative to thetotal mass of the glass printing ink or of the glass printing lacquer.

The glass printing ink according to the invention and the glass printinglacquer according to the invention may comprise one or more fillers. Thenature of the fillers is not particularly critical. They may be selectedfrom among conventional fillers used in printing inks, such as forexample, without being limited thereto, china clay, barium sulfate (inprecipitated form as blanc fixe), calcium carbonate, zinc sulfide,siliceous earth, talcum, aluminium silicate, aluminium hydrate and/orsilica. The quantity of filler used is generally in the range from 0 to50 wt. %, preferably from 10 to 30 wt. %, for example 20 wt. %, relativeto the total mass of the glass printing ink or of the glass printinglacquer.

The glass printing ink according to the invention or the glass printinglacquer according to the invention may also contain a thickener which islikewise selected from among conventional materials used for thispurpose in inks/lacquers. These include, without being limited thereto,for example pyrogenic silica, phyllosilicates and castor oilderivatives. The quantity of thickener used is usually in the range from0 to 10 wt. %, preferably from 1 to 5 wt. % and in particular from 1.5to 3 wt. %, relative to the total mass of the glass printing ink,depending on the type of pigment or glass printing lacquer.

In general, the glass printing ink according to the invention and theglass printing lacquer according to the invention also contain adefoamer and/or a levelling agent, in general in a quantity of 0.5 to2.5 wt. %, preferably 0.5 to 1.5 and in particular 1 wt. %, relative tothe total mass of the glass printing ink or of the glass printinglacquer. Defoamers may, for example, be selected not only from amongmodified acrylates or modified acrylate copolymers, but also, andpreferably, from compounds containing silicone. Levelling agentscomprise for example modified polyacrylates and polysiloxanes.

Preferably used stabilisers are Genorad 16 from Rahn and Florstab UV2from Kromachem, Park Industrial Centre, Tolpits Lane, Watford,Hertfordshire, WD 1 8SP, UK.

Prior to printing, a coupling agent may be added to the glass printingink and the glass printing lacquer in a quantity of 0.1 to 20 wt. %,preferably of 1 to 10 wt. %, relative to the total mass of the glassprinting ink or of the glass printing lacquer. These may compriseisocyanate coupling agents, for example aliphatic polyisocyanates, suchas hexamethylene diisocyanate (HDI), trimethylhexane diisocyanate(TMHDI), cycloaliphatic polyisocyanates such as isophorone diisocyanate(IPDI), hydrogenated xylylene diisocyanate (HXDI) ordiisocyanatodicyclohexylmethane (HMDI), and aromatic polyisocyanates,such as tolylene diisocyanate (TDI), xylylene diisocyanate (XDI),tetramethylxylylene diisocyanate (TMXDI) or diisocyanatodiphenylmethane(MDI). Commercially obtainable products are, for example, Desmodur E41or Desmodur N 75 (Bayer). Polyimides, such as polyethyleneimides,polycarbodiimides, may be used. Preferred coupling agents are, however,silane coupling agents, such as alkylsilanes, vinylsilanes,methacryloxysilanes, epoxysilanes, aminosilanes, urea-silanes,chlorosilanes and isocyanatosilanes. Aminosilanes are very particularlypreferred, such as gamma-aminopropyltriethoxysilane,gamma-aminopropyl-trimethoxy

silane, n-beta-(aminoethyl)-gamma-amino-propyl

trimethoxysilane, bis(gamma-trimethoxy

silyl-propyl)amine, N-phenyl-gamma-aminopropyltrimethoxysilane andN-beta-(amino

ethyl)-gamma-aminopropyl

methyl

dimethoxy

silane, and isocyanato

silanes, such as gamma-isocyanato

propyl-triethoxy

silane.

Articles which may be printed according to the invention include glass,ceramics, tiles and similar articles which are at least superficiallyvitreous. The invention accordingly also relates to the use of a glassprinting ink or of a glass printing lacquer for printing glass,ceramics, tiles and similar at least superficially vitreous substrates.

Such articles may be of any shape or form, such as a container, a sheet,a tile, a figure etc. In a preferred embodiment of the invention, thearticle is packaging glassware (beverage bottles, cosmetic containers)or commercial glassware.

As used according to the invention, the term “glass” is intended to meanglass, ceramics, tiles and similar vitreous materials.

Before printing, the glass is usually subjected to a pretreatment. Thismay comprise flame treatment.

One particularly effective pretreatment is the “UVitro” process fromIsimat, Ringelbacherstrasse 38-40, D-73479 Ellwangen. This process isexhaustively described in DE 100 19 926 A1 and U.S. Pat. No. 6,513,435B2. This process comprises, in a first step, treatment of a glasssurface with an oxidising flame (i.e. with an excess of oxygen) usuallyfor 3 to 4 seconds and, in a second step, treatment with a silicatisingflame (i.e. a flame into which a silicon compound, for exampletetramethoxysilane, is introduced), usually likewise for 3 to 4 seconds.

The glass is then printed. The printing method may comprise screenprinting, pad printing, offset printing, flexographic printing orgravure printing. Screen printing is preferred.

The glass printing ink or the glass printing lacquer is hardened with UVlight in a wavelength range of 200 to 400 nm over a period which issufficient to achieve complete hardening. Alternatively, the glassprinting ink or the glass printing lacquer may also be hardened withoutphotoinitiators using electron beam radiation.

The entire range of colour shades may be printed. If screen printing isused, a 100-40 to 180-27, preferably 140-34, printing screen ispreferably used, which yields an ink film thickness of 5-10 μm.Depending on the printing task and press, hardening proceeds usingconventional commercial medium pressure mercury lamps or gallium-dopedlamps at 80-400 W/cm, preferably 120 to 200 W/cm, which aresubstantially focussed. Exposure time is coupled with printing speed, asthe printing and exposure devices are coupled. In the case of flashexposure, a printing speed of 40-120 impressions/min is conventional.

After UV hardening, a thermal post-treatment step, for example at atemperature of 130 to 200° C., preferably of 130 to 170° C. and inparticular of 150° C. over a period of for example 20 to 40 min,preferably of 30 min, may optionally be performed.

The glass printing ink and the glass printing lacquer exhibit goodinterlayer adhesion and may be embossed with hot embossing foils.

The following Examples illustrate the invention.

EXAMPLES Example 1

UVitro pretreatment was carried out on a glass bottle (arcogas FTS 401flame treatment apparatus (Arcogas GmbH, Rotweg 25, D-71297 Mannheim)):

Burner: MB3 100

1. Preliminary flame treatment 300 l/min (air)—11 l/min (propane/butane)

2. UVitro 200 l/min (air)-7.5 l/min (propane/butane)

Duration: 3-4 seconds in each case

The bottles are then cooled to 35-40° C.

A glass printing ink of the following composition was producedbeforehand by dispersion using a 3-roll or bead mill:

Quantity Component Source (wt. %) 1,6-Hexanediol diacrylate LAROMER*HDDA 6 Stabiliser FLORSTAB UV-2** 1 Polysiloxane defoamer Tego Airex920*** 0.5 Tego Rad 2500**** 0.5 Photoinitiator 1 DAROCUR 1173/1173C 1Photoinitiator 2 Lucerin TPO 4.9 Co-initiator EBECRYL 7100***** 4Pigment TiO₂ 4 50% epoxy resin solution in ARALDITE 7072 50% in 25 HDDALaromer HDDA Nano-silicon dioxide in NANOCRYL XP 21/0793 10 melamineacrylate 35% MMA copolymer PARALOID B60 in HDDA, 19.6 solution in HDDA35% 100 *LAROMER is a trademark of BASF **FLORSTAB UV-2 is a stabiliserfrom Kromachem ***Tego Airex 920 is a defoamer from Tego Chemie ServiceGmbH, Goldschmidtstraβe 11, D-45127, Essen ****Tego Rad 2500 is alevelling agent from Tego *****Ebecryl 7100 is an amino-modifiedacrylate from Surface Specialities UCB

A mixture of the components stated in the above Table was mixed with 4wt. % of diaminosilane (for exampleN-beta-(aminoethyl)-gamma-aminopropyltrimethoxysilane orN-beta-(aminoethyl)-gamma-aminopropylmethyldimethoxysilane) or with 10wt. % of gamma-isocyanatopropyltriethoxysilane and printed onto thetreated glass bottle by screen printing on an ISIMAT 1000P printingpress with a 120-34 printing screen at 60 impressions/min.

Printability is good.

UV hardening proceeds in a UV dryer at approx. 600 mJ/cm².

The ink was not stoved.

Very good adhesive strength and scratch resistance in the undamaged inkfilm were achieved. In dishwasher testing in a Winterhalter industrialdishwasher, more than 100 washing cycles could be carried out withoutany change to the printed image.

The printed bottles could be filled with fruit juice on a filling linewithout suffering damage to the ink film.

Example 2

Quantity Component Source (wt. %) 1,6-Hexanediol diacrylate LAROMER*HDDA 6.6 Polysiloxane defoamer Tego Airex 920*** 0.5 Tego Rad 2500****0.5 Photoinitiator 1 DAROCUR 1173/1173C 1 Photoinitiator 2 Lucerin TPO4.9 Co-initiator EBECRYL 7100***** 4 Pigment TiO₂ 27.5 50% epoxy resinsolution in ARALDITE 7072 50% in 25 HDDA Laromer HDDA Acid-modifiedpolyester GENOMER 7154 30 acrylate 100 (footnotes see Example 1)without using a coupling agent by screen printing with a 140-34 printingscreen.

UV hardening was performed with a medium pressure mercury lamp at 2×120W/cm² at approx 5 m/min.

Good crosshatching resistance (adhesion) was achieved without stoving.Scratch resistance is very good in both the undamaged and damaged film.

In a further test, the ink was then stoved for 30 min at 150° C.

The printing ink for glass then achieved a crosshatching value to EN ISO2409 of GT 0 immediately after the condensed water test.

Using the glass printing ink of Example 1, good adhesion, scratchresistance and water resistance properties of the resultant ink filmwere accordingly achieved by two component printing without anyrequirement for stoving. Using glass printing ink 2, good adhesivestrength and scratch resistance properties could likewise be achieved bysingle component printing without subsequent stoving and, withsubsequent stoving, good water resistance of the resultant ink filmcould additionally be achieved. This amounts to a simplification of theprinting method in comparison with prior art printing methods.

It should be emphasized that the above-described embodiments of thepresent invention, particularly, any “preferred” embodiments, arepossible examples of implementations merely set forth for a clearunderstanding of the principles of the invention. Many variations andmodifications may be made to the above-described embodiments of theinvention without substantially departing from the spirit and principlesof the invention. All such modifications are intended to be includedherein within the scope of this disclosure and the present invention,and protected by the following claims.

Claimed is:
 1. A glass printing ink or glass printing lacquercomprising: at least two resins, which together yield a photo-hardenablemixture; and, at least one initiator, wherein a first resin of the atleast two resins comprises a bisphenol A based epoxy resin, diluted in aUV hardening monomer, and a second resin of the at least two resins isselected from the group consisting of: a melamine acrylate; anacid-modified polyester acrylate and an epoxy acrylate, and, whereineach initiator in the ink or lacquer is a radical photoinitiator.
 2. Theglass printing ink or glass printing lacquer of claim 1 wherein the atleast one initiator is selected from the group consisting of:1-hydroxycyclohexylacetophenone;2-methyl-1-[4-(methylthio-phenyl)-2-morpholinopropan]-1-one;2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one;bis(2,4,6-tri-methylbenzoyl)phenylphosphine oxide;2-hydroxy-2-methyl-1-phenyl-1-propanone; isopropylthioxanthone;2-chlorothioxanthone; benzophenone,2,4,6-trimethylbenzoyldiphenylphosphine oxide; ethyl2,4,6-trimethylbenzoyl-phenylphosphinate; methylbenzoyl formate; and,mixtures thereof.
 3. The glass printing ink or glass printing lacquer ofclaim 1 further comprising: a co-initiator.
 4. The glass printing ink orglass printing lacquer of claim 1, wherein the epoxy resin is used in aquantity of 1 to 90 wt. % relative to the weight of the glass printingink or of the glass printing lacquer:
 5. The glass printing ink or glassprinting lacquer of claim 1, wherein the second resin of the at leasttwo resins is used in a quantity of 5 to 90 wt. % relative to the weightof the glass printing ink or of the glass printing lacquer.
 6. The glassprinting ink or glass printing lacquer of claim 1, wherein the at leastone initiator is present in a total quantity of 1 to 12 wt. % relativeto the weight of the glass printing ink or of the glass printinglacquer.
 7. The glass printing ink or glass printing lacquer claim 1,wherein the UV hardening monomer is hexanediol diacrylate.
 8. The glassprinting ink or glass printing lacquer of claim 1, further comprising aUV hardening reactive diluent other than the UV hardening monomer. 9.The glass printing ink or glass printing lacquer of claim 1, furthercomprising a stabilizer.
 10. The glass printing ink or glass printinglacquer of claim 1, further comprising one or more pigments or dyes in aquantity of 0.5 to 50 wt. %, relative to the total weight of the ink.11. The glass printing ink or glass printing lacquer of claim 1, whereinthe bisphenol A based epoxy resin exhibits a weight average molecularweight in the range of substantially 800 to 1500.